Conventional recreational vehicles, such as travel trailers have a main vehicle body, wherein pop-up type trailers often include slide out beds at the opposite ends. The main body provides a primary living area while the beds extend out in cantilevered relation therewith to define sleeping areas. Alternatively, many trailers have fixed full-height sidewalls and do not require pullout beds.
Many such trailers, whether pop-up or fixed wall, include sideouts which are slide out living sections which are supported on the side of the main body and extend outwardly therefrom to provide expanded living space. The sideouts expand for use and retract inwardly into and are-stored within the area of the main body such as for transport.
Such beds and sideouts use various conventional telescoping drive assemblies to support and control extension/retraction of the beds and sideouts. Generally, the drive mechanisms including an arrangement of telescoping, rigid rails assemblies which comprise a stationary rail mounted on the main body and a movable rail, typically nested in the stationary rail, which said movable rail is attached to the respective bed or sideout and slides horizontally therewith. A drive arrangement is connected to the movable rail to control the movement of the rail and thereby control retraction or extension of the beds or sideouts.
While many configurations of cooperating, telescoping rails have been used in known drive mechanisms, it is an object of the invention to provide an improved drive mechanism, which provides advantages over prior systems.
The invention relates to a telescoping drive mechanism for slide out sections of recreational vehicles which drive mechanism has a low-profile to minimize the height of the vertical space required to mount the drive mechanism between the main trailer body and the slide out section. This low-profile mechanism is particularly advantageous for sideouts for which the height requirement is important. For beds, the telescoping rails extend parallel to and may be incorporated into the sidewalls of the main body and thereby straddle the living area which therefore provides greater flexibility in the vertical dimension. However, the sideouts typically extend sidewardly or perpendicularly from a middle portion of the sidewall such that the telescoping rails must be hidden within the interior living space.
The low profile drive mechanism uses a rail assembly having a low profile. Rather than use square tubing which has a fixed vertical dimension, the movable rail or ram is formed of an outer U-shaped channel with an inner C-channel welded within the interior slot of the outer channel. The inner channel rigidities the outer channel and essentially defines a tubular rail but has a shorter vertical dimension than the outer channel so that the thickness between the bottom and top tube walls is less than the vertical height of the outer channel sidewalls.
Further, the wall of the inner channel is stamped with a pattern of horizontally spaced apart slots which define a gear rack that is drivingly engaged with a rotating drive gear. The drive gear thereby drives the movable rail. Due to the reduced height of the inner channel, the drive gear projects upwardly into the outer channel with the overall vertical height requirements of the combined gear and movable rail being less than known rail arrangements. Furthermore, the inner rail is easier to manufacture than a machined gear rack of conventional construction.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the system and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.